Website speed optimization in Japan – measure, fix, and see the difference

Why website speed matters: lost visitors and rankings

Load time shows up directly in how people behave. A few seconds of blank screen is enough for many visitors to tap the back button. Phones vary a lot in network and processing power, so a site that feels fine on an office computer can be slow for someone on the train.

Google also uses loading speed and visual stability as part of its page experience signals. Content quality matters most for rankings, but when several pages are equally useful, the fast and stable one has an edge. If you run ads, every visitor who leaves before the page appears is budget spent for nothing.

• On a phone, text and photos take several seconds to appear
• The layout jumps while loading and buttons move under your finger
• The large hero image or slider on the home page is slow to show
• Analytics show a much higher bounce rate on mobile than on desktop
• Ad clicks are steady but inquiries or sales are very low

If any of these sound familiar, start by putting a number on your current speed.

How to measure website speed

Record your current results with the same tools and settings before changing anything. Without a baseline you cannot tell which fix worked. These free tools cover most needs:

• PageSpeed Insights: enter a URL and get mobile and desktop scores with specific suggestions
• Search Console (Core Web Vitals report): data from real visitors, grouped into slow and fast URLs
• Chrome DevTools (Lighthouse and Network): see which files are heavy and in what order they load

As a reference, Google's Core Web Vitals treat these as "good": the main image or heading appears within 2.5 seconds (LCP), the page responds to input within 200 milliseconds (INP), and layout shift stays at 0.1 or below (CLS). Scores vary a little on every run, so pick three to five key pages – the home page, a popular inner page, a product or service page – and track mainly the mobile results. For more detail on each metric, see improving Core Web Vitals.

What makes a website slow – and how to fix it

Most slow sites come down to a handful of causes. Working through them in order of impact often makes a visible difference quickly.

• Images: the most common cause is uploading photos straight from the camera. Resize them to their display size, convert to a lighter format such as WebP, and lazy-load images below the fold
• Scripts and plugins: remove unused features, duplicate tracking tags and heavy chat or social embeds, and defer anything that is not needed right away
• Fonts and CSS: limit web font families and weights, and drop unused styles. Japanese web fonts are especially large
• Caching: set up browser and page caching so repeat visits and popular pages load faster
• Hosting: a slow shared server or an old PHP version may call for a plan upgrade, a move, or a CDN

On photo-heavy sites, image optimization alone can make a big difference. Our guide to image SEO also covers file names and alt text.

WordPress speed tuning checklist

WordPress is flexible, but it tends to get heavier as themes and plugins pile up. Checking in this order makes the cause easier to find:

• Plugin audit: list every active plugin and switch off unused or overlapping ones
• Theme weight: check whether a multipurpose theme or page builder loads large amounts of CSS and JavaScript
• PHP and core updates: old PHP versions are slower and less secure; switch to a current version on the server
• Caching and image settings: add one caching or image plugin at a time and check the layout after each change
• Database cleanup: clear out old revisions and leftover data so the admin panel runs faster too

Changing many settings at once makes it hard to find what broke. Back up first, test on a staging copy, then apply to the live site. For search optimization on WordPress in general, see WordPress SEO.

Common speed optimization mistakes

When a higher score becomes the goal in itself, a site can end up faster but harder to use. Watch out for these:

• Deferring all scripts breaks forms, booking buttons or tracking tags
• Over-compressed images make product or project photos look cheap
• Caching shows outdated content or the wrong cart contents
• No baseline was recorded, so the improvement cannot be shown
• Only desktop results were checked and mobile stays slow

Pair every change with a new measurement and a quick test of forms and checkout, and these problems are easy to avoid.

How UNANOBO handles speed: measurement and a faster demo

UNANOBO starts with your current site's URL. We measure speed on mobile and desktop and list what is slowing the site down. Then we build a free demo – your pages rebuilt to be light, with your own brand and content – and show its results next to your current site, measured under the same conditions.

The process is free demo, feedback, launch, growth. The demo also makes it easier to decide whether tuning the current site is enough or a rebuild will be faster. The founder handles everything personally, from the first measurement to checks after launch, and all communication runs by message in Japanese or English.